As described in certain embodiments of U.S. Pat. No. 5,518,964, the disclosure of which is incorporated by reference herein, an element used in a microelectronic assembly may have elongated flexible leads extending along a surface of the element. Each lead has a first or terminal end permanently attached to the element and has a tip end offset from the terminal end. A second element having contacts thereon is engaged with the first element so that the tip ends of the leads are bonded to contacts on the second element. The first and second elements are then moved away from one another so as to deform the leads and provide vertically extensive leads extending between these elements. A compliant material may be introduced between the elements during or after such motion. The resulting structure allows relative movement of the elements without substantial stresses on the leads. This process can be used, for example, to make packaged semiconductor chips. One of the elements may be a connection component desirably having a flexible structure incorporating one or more dielectric layers, and the other one of the elements may be a chip, wafer or assemblage of chips. The leads may be provided either on the connection component or on the chips or wafer.
As described in U.S. Pat. No. 5,763,941, the disclosure of which is also incorporated by reference herein, a releasable lead structure may be made by providing a first region of a lead permanently connected to a component and a second region releasably connected to a surface of the component so that the second region can be peeled away from such surface. Desirably, the second region is attached to the underlying surface by a release interface having a peel strength of less than about 0.35.times.10.sup.6 dynes/cm; i.e., a peel strength of less then about 2 lbs. per linear inch. For example, certain low-energy vapor deposition processes such as electroless plating or chemical vapor deposition can deposit a thin layer of release metal forming a release interface with the underlying layer. The lead may incorporate a structural metal which may be the same as or different from the release metal. The release metal can be peeled away from the underlying layer. In other embodiments, the interface may include a layer of a first release metal securely bonded to the underlying layer and a second release metal on the lead, the first and second release metals being weakly bonded to one another so that the second region of the lead can be pulled away from the underlying layer, with the first release metal remaining on the underlying layer.